|Publication number||US5945898 A|
|Application number||US 08/657,815|
|Publication date||Aug 31, 1999|
|Filing date||May 31, 1996|
|Priority date||May 31, 1996|
|Also published as||EP0958614A1, EP0958614A4, WO1997045878A1|
|Publication number||08657815, 657815, US 5945898 A, US 5945898A, US-A-5945898, US5945898 A, US5945898A|
|Inventors||Jack W. Judy, Richard S. Muller|
|Original Assignee||The Regents Of The University Of California|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (14), Non-Patent Citations (26), Referenced by (129), Classifications (12), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates generally to micromachined structures, and more particularly to three-dimensional, thin-film, micromachined magnetic microactuators that may be selectively addressed.
Microelectromechanical systems often integrate micromechanical and microelectronic devices on the same silicon chip. These systems have many useful applications such as microsensors and microactuators. The accelerometer chips used to trigger air bag inflation in automobiles in the event of a collision are an example of a microsensor. Microvalves used to control fluidic circuits are examples of microactuators.
Microstructures can be made by photolithography and etching of deposited thin films to yield desired shapes. This is called "surface micromachining" because the thin films are deposited on a surface. The films are typically formed through the process of low-pressure chemical vapor deposition (LPCVD).
Integrated circuit and magnetic recording-head fabrication technologies can be used to machine microelectrical and micromechanical devices. These devices have mechanical and electrical components that typically require actuation to perform their intended functions. Such actuation can be accomplished by several methods including electrostatic and magnetic forces.
Components which create electrostatic forces are relatively easy to manufacture. These forces are large if operated with small gaps between electrodes, but small otherwise. They can be integrated with and controlled by integrated circuits.
The electrostatic forces typically used in micromachines are attractive rather than repulsive. Attractive forces may be disadvantageous when it is desired to move a structure away from a surface because an electrode that overhangs the surface may be required in such a case.
Magnetic forces are advantageous for certain microstructure designs. They have the characteristic of often being very large, especially those created using ferromagnetic materials. In addition, magnetic forces can be created by external sources, resulting in a substantial saving of space.
There are some disadvantages to using magnetic forces. Components which create magnetic forces are often difficult to manufacture. Also, manual assembly is usually required rather than a continuous batch process.
An object of the invention is to combine the features of electrostatic forces and magnetic forces within the same microstructure.
A further object is the design of a magnetic microactuator that may be batch-processed.
A selectively actuatable microstructure is provided having a base, a cantilevered element supported by at least one mechanical attachment attached to the base which permits the element to change its orientation, and at least one layer of magnetically-active material placed on one or more regions of a surface of the cantilevered element. The cantilevered element, the mechanical attachment, and the magnetically-active material are microfabricated in one batch process such that a selectively applied magnetic field can apply torque to the cantilevered element and cause it to move.
A first electrical connnection may be made to the cantilevered element, and a second electrical connnection may be made to the base region. A voltage source may be electrically connected between the first and second electrical connections to cause a Coulombic attractive force for holding the cantilevered element against movement in the presence of an applied magnetic field.
A number of the above selectively actuatable microstructures may be provided in an array so that each of the microstructures may be individually actuated by the selective switching of the corresponding voltage sources.
A selectively actuatable microstructure may also be made with a conducting pattern placed on the base region surrounding the cantilevered element such that a current can be passed through the conducting pattern to cause a magnetic field that is localized in the region of the cantilever for causing the cantilever to move.
This type of selectively actuatable microstructure may also be made in an array where only the selectively actuatable microstructures that have current passed through their corresponding conducting patterns are actuated. The conducting pattern for each may be, for example, magnetic coils.
The mechanical attachment may be at least one torsional support, a flexing material such as polyimide, or a hinged linkage.
The cantilevered element is highly reflective to direct optical beams for displays or communications.
The cantilevered element may be a strongly dispersive element in an acoustic beam such that the cantilevered element is easily detectable in an acoustic field such as a medical ultrasound system. The cantilevered element may also serve as a platform for an energy source device such as an ultrasound emitter, an electromagnetic radiation emitter, or an energy sensor.
An advantage of the invention is that high-quality arrays of microactuated structures can be batch-processed. Another advantage is the absence of interactions between adjacent structures and a very high areal density of structures that can be achieved. The invention can be advantageously used in optical scanners, displays, switches, gratings, microflow systems, sensors, micromirror systems, and in microphotonic applications such as beam chopping and steering.
Additional advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims.
The accompanying drawings, which are incorporated in and constitute a part of the specification, schematically illustrate the invention and, together with the general description given above and the detailed description given below, serve to explain the principles of the invention.
FIG. 1 is a schematic view of a magnetic microactuator according to a first embodiment of the invention.
FIGS. 2(a)-(d) are schematic views of the magnetic microactuator of FIG. 1, under the influence of various combinations of a magnetic force and an electrostatic clamping force.
FIG. 3 is a schematic plan view of a magnetic microactuator according to an embodiment of the invention having a restraining stop.
FIG. 4 is a schematic diagram of the implementation of an N×M system of magnetic microactuators used as an optical switch.
FIG. 5(a) is a schematic plan view of a magnetic microactuator according to a second embodiment of the invention, in the unselected or non-actuated condition.
FIG. 5(b) is a schematic plan view of a magnetic microactuator according to a second embodiment of the invention, in the selected or actuated condition.
FIG. 6 is a diagram illustrating a partial number of steps of a microfabrication technique for manufacturing a magnetic microactuator, these steps showing the process up to the step of etching holes where anchors will be placed.
FIG. 7 is a diagram illustrating a partial number of steps of a microfabrication technique for manufacturing a magnetic microactuator, these steps showing the process of constructing a magnetic plate.
The following patents describe various types of microelectromechanical structures as well as fabrication techniques for their manufacture: U.S. Pat. No. 4,674,319 entitled "Integrated Circuit Sensor"; U.S. Pat. No. 4,740,410 entitled "Micromechanical Elements and Methods for Their Fabrication"; and U.S. Pat. No. 5,252,881 entitled "IC-Processed Micromotors and Methods for their Fabrication". These patents are assigned to the assignee of the subject application and are hereby incorporated by reference in their entirety.
Referring now to FIG. 1, a magnetic microactuator 100 is shown having a magnetic plate 102 fabricated on a base 122. Magnetic plate 102 is generally a cantilevered element attached to base 122 by a mechanical attachment which permits the element to change its orientation.
Base 122 is fabricated by a deposition process such as those used in optical-resist technology. Base 122 is usually composed of an insulating layer 108 on top of a lower electrode layer 110. A hole is made through insulating layer 108 to allow a lower contact 114 to electrically connect lower electrode layer 110 with a clamping voltage supplied by a voltage source 116. An upper contact 112 is formed on top of insulating layer 108 to electrically connect the clamping voltage with the clamping system described below.
Magnetic plate 102 may be a rectangular beam, and it may constitute a single layer of magnetically-active material. Alternatively, magnetic plate 102 may have a layer of magnetically-active material plated onto a nonmagnetic material. More than one region of the magnetic plate may be so plated. The magnetic material can be one of various combinations of nickel, iron or other elements, and is usually ferromagnetic with a high saturation magnetization. Magnetic plate 102 is commonly about 430×130×15 cubic micrometers (length×width×height), although plates with their largest dimensions ranging roughly from 10 micrometers to more than a millimeter can be built.
Magnetic plate 102 is mounted to base 122 by mechanical attachments such as torsion beams 104 and 106 in a torsion-beam suspension system. In an alternative embodiment, only one beam may be used. Moreover, rather than a torsion-beam suspension, hinged linkages or folding mountings may be used. Flexible materials such as polyimide may also be used as a mechanical attachment.
Mechanical movement in this embodiment is performed by magnetic plate 102 rotating about torsion beams 104 and 106. The torsion beams 104 and 106 constrain the rotation of the magnetic film 102 to a single axis. Torsion beams 104 and 106 are secured against rotation by anchors 120 and 126. They are generally conductive and can be phosphorus-doped LPCVD polysilicon. They may be about 400×2.2×2.2 cubic micrometers (length×width×height). Beams may be used with length dimensions from about 10 micrometers to about a millimeter and cross-sectional dimensions from approximately 1.0 micrometer by 0.1 micrometers to 100.0 micrometers by 10.0 micrometers.
When a magnetic field 118 is applied, the resulting torque rotates magnetic plate 102 about torsion beams 104 and 106. Rotations of more than 90° can be achieved. Magnetic field 118 may often be, for example, several kiloamperes per meter. The torque caused by magnetic field 118 can be greater than 3.0 nanonewton-meters and is generally in the range of about 1 nanonewton-meter to about 100 nanonewton-meters.
The torque strains torsion beams 104 and 106. The final position of magnetic plate 102 is established when there is equilibrium between the restoring torque from strained torsion beams 104 and 106 and the torque on the system caused by magnetic field 118 on magnetic plate 102.
An electrostatic clamping system is implemented on base 122 to restrain magnetic plate 102 from rotation. The clamping system includes clamping voltage source 116, upper contact 112 for forming a first connection between magnetic plate 102 and voltage source 116, lower electrode layer 110, lower contact 114 for forming a second connection between base 122 and voltage source 116, and insulating layer 108. In use, an electrostatic clamping field applies a Coulombic force by placing clamping voltage source 116 across upper contact 112 and lower contact 114. A circuit is formed from lower electrode layer 110, clamping voltage source 116, upper contact 112, torsion beams 104 and 106, and magnetic plate 102. Magnetic plate 102, acting as an upper electrode, rotates back onto clamping area 124 to form one plate of a capacitor that couples to lower electrode layer 110.
The field created by clamping voltage source 116 is generally constant over clamping area 124. It is not necessary to concentrate the field, as the field will usually be strongest in the clamping area due to the close proximity of the magnetic plate to the lower electrode. Fringing fields may occur around the clamped plate, but these usually are not strong and do not affect the operation of the microactuator. The clamping voltage source 116 is switchable and can be as low as 5 volts or even lower. The clamping voltage source 116 may be generated by external sources such as power supplies or batteries, or by internal sources on the chip.
FIGS. 2(a)-(d) show the magnetic microactuator at positions according to the presence of an applied magnetic field 118 and the status of a clamping voltage 116. FIG. 2(b) is similar to FIG. 1. Magnetic field 118 acts to rotate magnetic plate 102 so that its equilibrium position is out of the plane of base 122. FIG. 2(a) shows the situation when magnetic field 118 is removed. Magnetic plate 102 rests on base 122 because torsion beams 104 and 106 hold the plate against rotation in the absence of magnetic field 118.
FIGS. 2(c) and (d) illustrate the effect of clamping voltage source 116. When such a clamping voltage is activated, magnetic plate 102 is clamped to base 122 by electrostatic attraction. This can occur whether or not a magnetic field 118 is applied (FIGS. 2(c) or (d)).
The user may choose materials, clamping voltage sources, and applied-magnetic fields to adjust the sensitivity of the microactuator for any particular purpose or application.
Referring to FIG. 3, if a simple binary on/off operation is desired, the system may be fabricated so that magnetic plate 102 is stable at only one of two positions. In this case, magnetic field 118 is designed to be strong enough to rotate magnetic plate 102 to a mechanical restraining stop 135, restraining magnetic plate 102 against further rotation.
It should be noted that magnetic plate 102 need not be a rectangular beam. Other structures having magnetic portions can be used which can move by, for example, sliding or rolling.
A large array of such microstructures may be fabricated on a chip, and each can be selectively actuated by, for example, an electrostatic address arrangement.
An application of such an array is an optical switch. In this case, each magnetic plate 102 may act as a mirror; a suitable mirror coating may be deposited on each to enhance reflectivity if desired. Referring to FIG. 4, an N-by-M array of individually-controlled microstructures is diagrammed. For clarity, only two optical inputs 401 and 403, and two optical outputs 451 and 453 are shown. The inputs and outputs are usually collimated. The N inputs (401, 403, . . . ) are along one side of the array and the M outputs (451, 453, . . . ) are along an adjacent side. The switching elements are the array of microstructures 102. In each element of the array, magnetic plate 102 is oriented at 45° to an incoming optical beam.
If the mth element along one of the N input beams is actuated, that beam is reflected into the mth of the M outputs. All but one mirror in a given input line is held down by the clamping electrostatic voltages on the elements. The actuated mirror selects the output for that line.
Another application may be an optical display. A large array of structures are addressed individually forming the reflected image. The display rate is related to the rate at which the structures can be addressed. At atmospheric pressure, the structures may be addressable at rates on the order of a kilohertz. For operation with video systems having higher rate requirements, the structures may be encapsulated in a vacuum enclosure.
A further application is an optical scanner. In this application, light incident on the magnetic plates 102 can be reflected at an angle controlled by the deflection.
Yet a further application is a sensitive probe of magnetic fields. In this application, varying magnetic fields on the surface can provoke a varying response in the array.
In a further application, an array of magnetic plates may be made highly reflective to direct optical beams for displays or communications.
In another application, an array of cantilevered elements may be a strongly dispersive element in an acoustic beam such that the cantilevered element is easily detectable in an acoustic field such as a medical ultrasound system. An array of cantilevered elements may also serve as a platform for an energy source device such as an ultrasound emitter, an electromagnetic radiation emitter, or an energy sensor.
Referring to FIGS. 5a and 5b, a second embodiment includes a magnetic plate 102 which is actuated by a conducting pattern such as an encircling coil 302. In this embodiment, coil 302, which is generally planar and driven by a current source 316, generates a field sufficient to rotate magnetic plate 102 out of the plane of base 122. As in the embodiment above, magnetic plate 122 may be attached to base 122 by mechanical attachments 320.
FIG. 6 illustrates a fabrication technique which may be used to construct the magnetic microactuator. Generally, the cantilevered element such as magnetic plate 102, the mechanical attachments such as torsion beam 104 and 106, and the plating of a magnetically-active material are fabricated in a single batch process.
As shown in FIG. 6(a), a substrate such as a silicon wafer 401 is loaded into a deposition chamber (not shown). The lower electrode 110 may be formed first either by heavily doping the surface of the silicon wafer or by depositing a conductive layer of a material such as doped polycrystalline silicon. An insulating dielectric layer 403 such as silicon nitride is then deposited. A sacrificial layer 405 is deposited on top of the dielectric layer 403. Sacrificial layer 405 is, for example, silicon dioxide doped with phosphorus.
As shown in FIG. 6(b), holes are etched through sacrificial layer 405 to insulating layer 403, creating positions for anchors 120. Holes are also etched (not shown) through both sacrificial layer 405 and insulating layer 403 to provide lower electrical contact 114.
Referring to FIG. 7(a), a conductive layer 407 is then deposited above the sacrificial layer 405. Conductive layer 407 serves as the mechanical material from which the magnetic plate, torsion beams, and anchor are eventually constructed. This conductive material may be, for example, phosphorus-doped polycrystalline silicon or a heavily-doped silicon substrate. This material is deposited through the holes in sacrificial layer 405 to form anchors 120 and 126 (shown in FIG. 7(a)). This conductive layer may undergo additional processing such as annealing to improve its mechanical properties. After processing, conductive layer 407 is etched to form the mechanical structure.
Before the mechanical structure can be used as magnetic plate 102, a magnetic layer must be deposited. An electroplating seed layer 509 is deposited first on the mechanical structure to prepare it for electroplating. Electroplating seed layer 509 may be, for example, nickel, an alloy of iron-nickel, or an alloy of copper-chromium.
A photoresist plating mask 511 is formed (FIG. 7(b)). This mask may be, for example, two micrometers thick. A ferromagnetic material is electroplated through the mask (FIG. 7(c)). The deposited ferromagnetic material may be nickel, iron, cobalt, or an alloy of these and other materials. The ferromagnetic material is electroplated to a thickness many times that of photoresist plating mask 511, causing the ferromagnetic material to "mushroom" over the edges of the mask. The ferromagnetic layer 513, together with layer 407, forms magnetic plate 102.
Photoresist plating mask 511 is then removed along with the unplated areas of electroplating seed layer 509 (FIG. 7(d)), these having previously been covered by photoresist plating mask 511. Sacrificial layer 405 is sputter-etched away to release magnetic plate 102, freeing it to rotate (FIG. 7(e)). The etch used may be a concentrated two-minute hydrogen fluorine bath.
The present invention has been described in terms of preferred embodiments. The invention, however, is not limited to the embodiments depicted and described. Rather, the scope of the invention is defined by the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US5398011 *||May 17, 1993||Mar 14, 1995||Sharp Kabushiki Kaisha||Microrelay and a method for producing the same|
|US5411769 *||Sep 29, 1993||May 2, 1995||Texas Instruments Incorporated||Method of producing micromechanical devices|
|US5424866 *||Aug 16, 1993||Jun 13, 1995||Kikinis; Dan||Dynamic holographic display with cantilever|
|US5469302 *||May 20, 1994||Nov 21, 1995||Daewoo Electronics Co., Ltd.||Electrostrictive mirror actuator for use in optical projection system|
|US5505807 *||Jul 21, 1994||Apr 9, 1996||Daewoo Electronics Co., Ltd.||Actuated mirror array and method for the fabricating thereof|
|US5506720 *||Sep 27, 1994||Apr 9, 1996||Daewoo Electronics Co., Ltd.||Method for manufacturing an electrodisplacive actuated mirror array|
|US5552923 *||Oct 13, 1994||Sep 3, 1996||Daewoo Electronics Co., Ltd.||Array of electrodisplacive actuated mirrors and method for the manufacture thereof|
|US5557132 *||Dec 6, 1994||Sep 17, 1996||Nec Corporation||Semiconductor relay unit|
|US5585956 *||Jul 29, 1994||Dec 17, 1996||Daewoo Electronics Co, Ltd.||Electrostrictive actuated mirror array|
|US5606452 *||Oct 25, 1995||Feb 25, 1997||Daewoo Electronics Co., Ltd.||Array of thin film actuated mirrors and method for the manufacture thereof|
|US5610757 *||Jul 20, 1995||Mar 11, 1997||Daewoo Electronics Co., Ltd.||Thin film actuated mirror array for use in an optical projection system|
|US5629918 *||Jan 20, 1995||May 13, 1997||The Regents Of The University Of California||Electromagnetically actuated micromachined flap|
|US5655665 *||Dec 9, 1994||Aug 12, 1997||Georgia Tech Research Corporation||Fully integrated micromachined magnetic particle manipulator and separator|
|US5724015 *||Jun 1, 1995||Mar 3, 1998||California Institute Of Technology||Bulk micromachined inductive transducers on silicon|
|1||Akiyama, Terunobu et al., "A New Step Motion of Polysilicon Microstructures", Proceedings IEEE (Feb., 1993) 272-277.|
|2||*||Akiyama, Terunobu et al., A New Step Motion of Polysilicon Microstructures , Proceedings IEEE (Feb., 1993) 272 277.|
|3||Buhler, et al., "Double Pass Metallization for CMOS Aluminum Actuators", Transducers '95-Eurosensors IX (Jun., 1995) 360-363.|
|4||*||Buhler, et al., Double Pass Metallization for CMOS Aluminum Actuators , Transducers 95 Eurosensors IX (Jun., 1995) 360 363.|
|5||Chang et al., "A Fully Integrated Surface Micromachined Magnetic Microactuator with a Multimedia Meander Magnetic Core," Journal of Micromechanical Systems, V.2, No. 1, Mar. 1993.|
|6||*||Chang et al., A Fully Integrated Surface Micromachined Magnetic Microactuator with a Multimedia Meander Magnetic Core, Journal of Micromechanical Systems , V.2, No. 1, Mar. 1993.|
|7||Chang Liu, et al., "Out-of-Plane Permalloy Magnetic Actuators for Delta-Wing Control", IEEE, Micro Electro Mechanical Systems, Jan. 29, Feb. 2, 1995, Cat. No. 95CH35754, pp. 7-12.|
|8||*||Chang Liu, et al., Out of Plane Permalloy Magnetic Actuators for Delta Wing Control , IEEE, Micro Electro Mechanical Systems , Jan. 29, Feb. 2, 1995, Cat. No. 95CH35754, pp. 7 12.|
|9||*||Chung, Seok Whan, et al., Design and Fabrication of Micro Mirror Supported by Electroplated Nickel Posts , Transducers 95 Eurosensors IX (Jun., 1995) 312 315.|
|10||Chung, Seok-Whan, et al., "Design and Fabrication of Micro Mirror Supported by Electroplated Nickel Posts", Transducers '95-Eurosensors IX (Jun., 1995) 312-315.|
|11||Goosen, J.F.L. et al, "Object Positioning Using a Surface Micromachined Distributed System", Transducers '95-Eurosensors IX (Jun., 1995) 396-399.|
|12||*||Goosen, J.F.L. et al, Object Positioning Using a Surface Micromachined Distributed System , Transducers 95 Eurosensors IX (Jun., 1995) 396 399.|
|13||J. Buhler, et al., "Double Pass Metallization for CMOS Aluminum Actuators", The 8th Int. Conference on Solid-State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers, Jun. 25-29, 1995, Stockholm Sweden, vol. 1, pp. 360-363.|
|14||*||J. Buhler, et al., Double Pass Metallization for CMOS Aluminum Actuators , The 8th Int. Conference on Solid State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers , Jun. 25 29, 1995, Stockholm Sweden, vol. 1, pp. 360 363.|
|15||J. Goosen, et al., "Object Positioning Using a Surface Micromachined Distributed System", The 8th Int. Conference on Solid-State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers, Jun. 25-29, 1995 Stockholm Sweden, vol. 1, pp. 396-399.|
|16||*||J. Goosen, et al., Object Positioning Using a Surface Micromachined Distributed System , The 8th Int. Conference on Solid State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers , Jun. 25 29, 1995 Stockholm Sweden, vol. 1, pp. 396 399.|
|17||Liu, Chang, et al., "Out-of-Plane Permalloy Magnetic Actuators for Delta-Wing Control", Proceedings IEEE (Jan. & Feb. 1995) 7-12.|
|18||*||Liu, Chang, et al., Out of Plane Permalloy Magnetic Actuators for Delta Wing Control , Proceedings IEEE (Jan. & Feb. 1995) 7 12.|
|19||M. Shikida, et al., "Fabrication of an Electrostatic Microactuator with an S-Shaped Film", The 8th Int. Conference on Solid-State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers, Jun. 25-29, 1995, Stockholm Sweden, vol. 1, pp. 426-429.|
|20||*||M. Shikida, et al., Fabrication of an Electrostatic Microactuator with an S Shaped Film , The 8th Int. Conference on Solid State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers , Jun. 25 29, 1995, Stockholm Sweden, vol. 1, pp. 426 429.|
|21||*||Seok Whan Chung, et al., Design and Fabrication of Micro Mirror Supported by Electroplated Nickel Posts , The 8th Int. Conference on Solid State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers , Jun. 25 29, 1995, Stockholm Sweden, vol. 1, pp. 312 315.|
|22||Seok-Whan Chung, et al., "Design and Fabrication of Micro Mirror Supported by Electroplated Nickel Posts", The 8th Int. Conference on Solid-State Sensors and Actuators and Eurosensors IX, Digest of Technical Papers, Jun. 25-29, 1995, Stockholm Sweden, vol. 1, pp. 312-315.|
|23||Shikida, Mitsuhiro, et al., "Fabrication of an Electrostatic Microactuator with an S-Shaped Film", Transducers '95-Eurosensors IX (Jun. 1995) 426-429.|
|24||*||Shikida, Mitsuhiro, et al., Fabrication of an Electrostatic Microactuator with an S Shaped Film , Transducers 95 Eurosensors IX (Jun. 1995) 426 429.|
|25||T. Akiyama, et al., "A New Step Motion of Polysilicon Microstructures", IEEE, Micro Electro Mechanical Systems, An investigation of Micro Structures, Sensors, Actuators, Machines and Systems, Feb. 7-10, 1993, Cat. No. 93CH3265-6, pp. 272-277.|
|26||*||T. Akiyama, et al., A New Step Motion of Polysilicon Microstructures , IEEE, Micro Electro Mechanical Systems , An investigation of Micro Structures, Sensors, Actuators, Machines and Systems, Feb. 7 10, 1993, Cat. No. 93CH3265 6, pp. 272 277.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6124650 *||Oct 15, 1999||Sep 26, 2000||Lucent Technologies Inc.||Non-volatile MEMS micro-relays using magnetic actuators|
|US6140737 *||Dec 2, 1999||Oct 31, 2000||Lucent Technologies Inc.||Apparatus and method for charge neutral micro-machine control|
|US6411754 *||Aug 25, 2000||Jun 25, 2002||Corning Incorporated||Micromechanical optical switch and method of manufacture|
|US6445840||Jan 13, 2000||Sep 3, 2002||Omm, Inc.||Micromachined optical switching devices|
|US6445841||Jan 13, 2000||Sep 3, 2002||Omm, Inc.||Optomechanical matrix switches including collimator arrays|
|US6449406||Jan 13, 2000||Sep 10, 2002||Omm, Inc.||Micromachined optomechanical switching devices|
|US6453083||Jan 13, 2000||Sep 17, 2002||Anis Husain||Micromachined optomechanical switching cell with parallel plate actuator and on-chip power monitoring|
|US6469602||Feb 2, 2000||Oct 22, 2002||Arizona State University||Electronically switching latching micro-magnetic relay and method of operating same|
|US6473545||Feb 26, 2002||Oct 29, 2002||Corning Incorporated||Micromechanical optical switch|
|US6496612 *||May 3, 2000||Dec 17, 2002||Arizona State University||Electronically latching micro-magnetic switches and method of operating same|
|US6498870||Apr 20, 1998||Dec 24, 2002||Omm, Inc.||Micromachined optomechanical switches|
|US6526198||Jan 17, 2002||Feb 25, 2003||Omm, Inc.||Micromachined optomechanical switches|
|US6556741||Oct 25, 2000||Apr 29, 2003||Omm, Inc.||MEMS optical switch with torsional hinge and method of fabrication thereof|
|US6600474||Mar 4, 1999||Jul 29, 2003||Flixel Ltd.||Micro-mechanical flat-panel display|
|US6614628||Jan 18, 2002||Sep 2, 2003||Seagate Technology Llc||Moving coil micro actuator with reduced rotor mass|
|US6633212||Mar 6, 2001||Oct 14, 2003||Arizona State University||Electronically latching micro-magnetic switches and method of operating same|
|US6676813||Mar 13, 2002||Jan 13, 2004||The Regents Of The University Of California||Technology for fabrication of a micromagnet on a tip of a MFM/MRFM probe|
|US6710350 *||Mar 5, 2002||Mar 23, 2004||Ge Medical Systems Information Technologies, Inc.||Radiation detector with microphotonic optical switches to route light in an imaging system|
|US6765766||Jun 4, 2001||Jul 20, 2004||Seagate Technology Llc||Bonding tub improved electromagnetic microactuator in disc drives|
|US6778350||Jun 8, 2001||Aug 17, 2004||Seagate Technology Llc||Feed forward control of voice coil motor induced microactuator disturbance|
|US6785038||Jan 17, 2001||Aug 31, 2004||Optical Coating Laboratory, Inc.||Optical cross-connect with magnetic micro-electro-mechanical actuator cells|
|US6791731||Dec 27, 2002||Sep 14, 2004||Electronics And Telecommunications Research Institute||Micro-optical switch and method for manufacturing the same|
|US6794965||Jan 18, 2002||Sep 21, 2004||Arizona State University||Micro-magnetic latching switch with relaxed permanent magnet alignment requirements|
|US6801681||Jan 17, 2001||Oct 5, 2004||Optical Coating Laboratory, Inc.||Optical switch with low-inertia micromirror|
|US6819820||Aug 18, 2001||Nov 16, 2004||Analog Devices, Inc.||Use of applied force to improve MEMS switch performance|
|US6831539||Aug 28, 2003||Dec 14, 2004||Seagate Technology Llc||Magnetic microactuator for disc with integrated head connections and limiters drives|
|US6888979||Apr 12, 2001||May 3, 2005||Analog Devices, Inc.||MEMS mirrors with precision clamping mechanism|
|US6891988||May 11, 2001||May 10, 2005||Analog Devices, Inc.||Magnetic position detection apparatus for micro machined optical element|
|US6894592||May 20, 2002||May 17, 2005||Magfusion, Inc.||Micromagnetic latching switch packaging|
|US6897539 *||Apr 12, 2002||May 24, 2005||The Regents Of The University Of California||Method for directing an optical beam and a method for manufacturing an apparatus for directing an optical beam|
|US6906511||May 8, 2001||Jun 14, 2005||Analog Devices, Inc.||Magnetic position detection for micro machined optical element|
|US6962830 *||Feb 23, 2000||Nov 8, 2005||The Regents Of The University Of California||Global mechanical stop|
|US6987435||Jun 27, 2002||Jan 17, 2006||Electronics And Telecommunications Research Institute||Micro-electromechanical actuators|
|US7027682 *||Jul 11, 2001||Apr 11, 2006||Arizona State University||Optical MEMS switching array with embedded beam-confining channels and method of operating same|
|US7071431||Mar 6, 2001||Jul 4, 2006||Arizona State University||Electronically latching micro-magnetic switches and method of operating same|
|US7133185 *||Aug 27, 2004||Nov 7, 2006||Industrial Technology Research Institute||MEMS optical switch with self-assembly structure|
|US7136588 *||Dec 22, 2000||Nov 14, 2006||Cheetah Omni, Llc||Apparatus and method for optical add/drop multiplexing|
|US7168249 *||Nov 22, 2005||Jan 30, 2007||Microsoft Corporation||Microelectrical mechanical structure (MEMS) optical modulator and optical display system|
|US7177065||Oct 2, 2003||Feb 13, 2007||Nikon Corporation||Optical element, thin film structure, optical switch, and method of manufacturing optical element|
|US7183633||Mar 1, 2002||Feb 27, 2007||Analog Devices Inc.||Optical cross-connect system|
|US7183884||Oct 15, 2003||Feb 27, 2007||Schneider Electric Industries Sas||Micro magnetic non-latching switches and methods of making same|
|US7189359 *||Jul 28, 2004||Mar 13, 2007||National Tsing Hua University||Electrowetting electrode device with electromagnetic field for actuation of magnetic-bead biochemical detection system|
|US7202765||May 14, 2004||Apr 10, 2007||Schneider Electric Industries Sas||Latchable, magnetically actuated, ground plane-isolated radio frequency microswitch|
|US7215229||Dec 22, 2003||May 8, 2007||Schneider Electric Industries Sas||Laminated relays with multiple flexible contacts|
|US7250838||Apr 4, 2005||Jul 31, 2007||Schneider Electric Industries Sas||Packaging of a micro-magnetic switch with a patterned permanent magnet|
|US7253710||Jul 13, 2005||Aug 7, 2007||Schneider Electric Industries Sas||Latching micro-magnetic switch array|
|US7266867||Sep 17, 2003||Sep 11, 2007||Schneider Electric Industries Sas||Method for laminating electro-mechanical structures|
|US7300815||Apr 25, 2005||Nov 27, 2007||Schneider Electric Industries Sas||Method for fabricating a gold contact on a microswitch|
|US7301177||May 14, 2004||Nov 27, 2007||The Regents Of The University Of California||Method for directing an optical beam and a method for manufacturing an apparatus for directing an optical beam|
|US7327211||Mar 21, 2005||Feb 5, 2008||Schneider Electric Industries Sas||Micro-magnetic latching switches with a three-dimensional solenoid coil|
|US7342473||Apr 7, 2005||Mar 11, 2008||Schneider Electric Industries Sas||Method and apparatus for reducing cantilever stress in magnetically actuated relays|
|US7353593||May 9, 2003||Apr 8, 2008||Simon Fraser University||Method for assembling micro structures|
|US7372349||Jul 10, 2006||May 13, 2008||Schneider Electric Industries Sas||Apparatus utilizing latching micromagnetic switches|
|US7391290||Sep 6, 2005||Jun 24, 2008||Schneider Electric Industries Sas||Micro magnetic latching switches and methods of making same|
|US7420447||Jun 14, 2005||Sep 2, 2008||Schneider Electric Industries Sas||Latching micro-magnetic switch with improved thermal reliability|
|US7420724||Sep 14, 2001||Sep 2, 2008||Duke University||Scanner apparatus having electromagnetic radiation devices coupled to MEMS actuators|
|US7449693 *||Jun 12, 2006||Nov 11, 2008||Texas Instruments Incorporated||System and method for radiation detection and imaging|
|US7482899||Sep 24, 2006||Jan 27, 2009||Jun Shen||Electromechanical latching relay and method of operating same|
|US7557470||Feb 22, 2007||Jul 7, 2009||Massachusetts Institute Of Technology||6-axis electromagnetically-actuated meso-scale nanopositioner|
|US7706039||Jul 10, 2008||Apr 27, 2010||Duke University||Scanner apparatus having electromagnetic radiation devices coupled to MEMS actuators|
|US7772529||Aug 10, 2010||Honeywell International Inc.||Selective permalloy anisotropy|
|US8068002||Nov 29, 2011||Magvention (Suzhou), Ltd.||Coupled electromechanical relay and method of operating same|
|US8159320||Apr 17, 2012||Meichun Ruan||Latching micro-magnetic relay and method of operating same|
|US8400697||Mar 19, 2013||Duke University||Scanner apparatus having electromagnetic radiation devices coupled to MEMS actuators|
|US8519810||Apr 11, 2012||Aug 27, 2013||Meichun Ruan||Micro-magnetic proximity sensor and method of operating same|
|US8614742 *||Jun 6, 2007||Dec 24, 2013||Palo Alto Research Center Incorporated||Miniature low cost pan/tilt magnetic actuation for portable and stationary video cameras|
|US20020121951 *||Jan 18, 2002||Sep 5, 2002||Jun Shen||Micro-magnetic latching switch with relaxed permanent magnet alignment requirements|
|US20020163053 *||Apr 12, 2002||Nov 7, 2002||The Regents Of The University Of California, A California Corporation||Method for directing an optical beam and a method for manufacturing an apparatus for directing an optical beam|
|US20020167307 *||May 11, 2001||Nov 14, 2002||Murali Chaparala||Magnetic position detection apparatus for micro machined optical element|
|US20020167309 *||May 8, 2001||Nov 14, 2002||Murali Chaparala||Magnetic position detection for micro machined optical element|
|US20020196110 *||May 29, 2002||Dec 26, 2002||Microlab, Inc.||Reconfigurable power transistor using latching micromagnetic switches|
|US20030025580 *||May 20, 2002||Feb 6, 2003||Microlab, Inc.||Apparatus utilizing latching micromagnetic switches|
|US20030137374 *||Aug 12, 2002||Jul 24, 2003||Meichun Ruan||Micro-Magnetic Latching switches with a three-dimensional solenoid coil|
|US20030168603 *||Mar 5, 2002||Sep 11, 2003||Ge Medical Systems Information Technologies, Inc.||Radiation detector with microphotonic optical switches to route light in an imaging system|
|US20030169135 *||Dec 23, 2002||Sep 11, 2003||Jun Shen||Latching micro-magnetic switch array|
|US20030179056 *||Dec 23, 2002||Sep 25, 2003||Charles Wheeler||Components implemented using latching micro-magnetic switches|
|US20030179057 *||Jan 8, 2003||Sep 25, 2003||Jun Shen||Packaging of a micro-magnetic switch with a patterned permanent magnet|
|US20030192179 *||May 9, 2003||Oct 16, 2003||Johnstone Robert W.||Method for assembling micro structures and related apparatus|
|US20030222740 *||Mar 18, 2003||Dec 4, 2003||Microlab, Inc.||Latching micro-magnetic switch with improved thermal reliability|
|US20040013346 *||Mar 6, 2001||Jan 22, 2004||Meichun Ruan||Electronically latching micro-magnetic switches and method of operating same|
|US20040080484 *||Nov 22, 2001||Apr 29, 2004||Amichai Heines||Display devices manufactured utilizing mems technology|
|US20040091202 *||Oct 21, 2003||May 13, 2004||Lg Electronics Inc.||Optical switch|
|US20040125432 *||Oct 2, 2003||Jul 1, 2004||Tohru Ishizuya||Optical element, thin film structure, optical switch, and method of manufacturing optical element|
|US20040183633 *||Sep 17, 2003||Sep 23, 2004||Magfusion, Inc.||Laminated electro-mechanical systems|
|US20040211655 *||May 14, 2004||Oct 28, 2004||Behrang Behin|
|US20040218244 *||Sep 14, 2001||Nov 4, 2004||Smith Stephen W.||Scanner apparatus having electromagnetic radiation devices coupled to mems actuators|
|US20040227599 *||May 14, 2004||Nov 18, 2004||Jun Shen||Latachable, magnetically actuated, ground plane-isolated radio frequency microswitch and associated methods|
|US20040247237 *||Aug 18, 2001||Dec 9, 2004||Murali Chaparala||Use of applied force to improve mems switch performance|
|US20050056569 *||Jul 28, 2004||Mar 17, 2005||National Tsing Hua University||Electrowetting electrode device with electromagnetic field for actuation of magnetic-bead biochemical detection system|
|US20050057329 *||Dec 22, 2003||Mar 17, 2005||Magfusion, Inc.||Laminated relays with multiple flexible contacts|
|US20050083156 *||Oct 15, 2003||Apr 21, 2005||Magfusion, Inc||Micro magnetic non-latching switches and methods of making same|
|US20050083157 *||Oct 15, 2003||Apr 21, 2005||Magfusion, Inc.||Micro magnetic latching switches and methods of making same|
|US20050088175 *||Oct 25, 2003||Apr 28, 2005||Honeywell International Inc.||Permalloy magnetization reversal sensor|
|US20050088404 *||Dec 3, 2002||Apr 28, 2005||Amichai Heines||Display devices|
|US20050206986 *||May 16, 2005||Sep 22, 2005||Nikon Corporation||Micro-actuator utilizing electrostatic and lorentz forces, and micro-actuator device, optical switch and optical switch array using the same|
|US20050286110 *||Aug 27, 2004||Dec 29, 2005||Industrial Technology Research Institute||MEMS optical switch with self-assembly structure|
|US20060044088 *||Feb 17, 2005||Mar 2, 2006||Magfusion, Inc.||Reconfigurable power transistor using latching micromagnetic switches|
|US20060049826 *||Mar 1, 2002||Mar 9, 2006||Onix Microsystems||Optical cross-connect system|
|US20060049900 *||Mar 21, 2005||Mar 9, 2006||Magfusion, Inc.||Micro-magnetic latching switches with a three-dimensional solenoid coil|
|US20060055491 *||Apr 4, 2005||Mar 16, 2006||Magfusion, Inc.||Packaging of a micro-magnetic switch with a patterned permanent magnet|
|US20060070379 *||Nov 22, 2005||Apr 6, 2006||Microsoft Corporation||Microelectrical mechanical structure (MEMS) optical modulator and optical display system|
|US20060082427 *||Apr 7, 2005||Apr 20, 2006||Magfusion, Inc.||Method and apparatus for reducing cantilever stress in magnetically actuated relays|
|US20060114084 *||Jun 14, 2005||Jun 1, 2006||Magfusion, Inc.||Latching micro-magnetic switch with improved thermal reliability|
|US20060114085 *||Jun 14, 2005||Jun 1, 2006||Magfusion, Inc.||System and method for routing input signals using single pole single throw and single pole double throw latching micro-magnetic switches|
|US20060146470 *||Jul 13, 2005||Jul 6, 2006||Magfusion, Inc.||Latching micro-magnetic switch array|
|US20060204775 *||Mar 10, 2005||Sep 14, 2006||Honeywell International, Inc.||Selective permalloy anisotropy|
|US20070018762 *||Jul 10, 2006||Jan 25, 2007||Magfusion, Inc.||Apparatus utilizing latching micromagnetic switches|
|US20070047113 *||Jul 20, 2006||Mar 1, 2007||Capella Photonics, Inc.||High fill-factor bulk silicon mirrors with reduced effect of mirror edge diffraction|
|US20070075809 *||Sep 24, 2006||Apr 5, 2007||Jun Shen||Electromechanical Latching Relay and Method of Operating Same|
|US20070284531 *||Jun 12, 2006||Dec 13, 2007||Texas Instruments Incorporated||System and method for radiation detection and imaging|
|US20080266636 *||Jul 10, 2008||Oct 30, 2008||Duke University||Scanner Apparatus Having Electromagnetic Radiation Devices Coupled to MEMS Acuators|
|US20080303900 *||Jun 6, 2007||Dec 11, 2008||Palo Alto Research Center Incorporated||Miniature Low Cost Pan/Tilt Magnetic Actuation For Portable And Stationary Video Cameras|
|US20090261927 *||Oct 22, 2009||Jun Shen||Coupled Electromechanical Relay and Method of Operating Same|
|US20100238532 *||Sep 23, 2010||Duke University University of North Carolina||Scanner apparatus having electromagnetic radiation devices coupled to mems actuators|
|US20110063055 *||Sep 14, 2009||Mar 17, 2011||Meichun Ruan||Latching micro-magnetic relay and method of operating same|
|CN100415635C||Oct 17, 2003||Sep 3, 2008||Nxp股份有限公司||Method for manufacturing a micro-electromechanical device and micro-electromechanical device obtained therewith|
|EP1120677A2 *||Dec 22, 2000||Aug 1, 2001||Cronos Integrated Microsystems, Inc.||MEMS optical cross-connect switch|
|EP1207541A1 *||Nov 12, 2001||May 22, 2002||Little Things Factory GmbH||Microswitch with reinforced contact force|
|EP1413913A2 *||Oct 23, 2003||Apr 28, 2004||Lg Electronics Inc.||Optical cross-connect switch|
|EP1437325A1 *||Sep 5, 2002||Jul 14, 2004||Nikon Corporation||MICRO−ACTUATOR, MICRO−ACTUATOR DEVICE, OPTICAL SWITCH AND OPTICAL SWITCH ARRAY|
|EP1473582A1 *||Dec 19, 2002||Nov 3, 2004||Nikon Corporation||Optical element, thin-film structural body, optical switch, and optical element manufacturing method|
|EP1577696A2 *||Oct 23, 2003||Sep 21, 2005||Lg Electronics Inc.||Optical switch|
|WO2002023251A2 *||Sep 14, 2001||Mar 21, 2002||Duke University||Scanner apparatus having optical elements coupled to mems acuators|
|WO2002023251A3 *||Sep 14, 2001||Feb 6, 2003||Stephen M Bobbio||Scanner apparatus having optical elements coupled to mems acuators|
|WO2002042826A2 *||Nov 22, 2001||May 30, 2002||Flixel Ltd.||Microelectromechanical display devices|
|WO2002042826A3 *||Nov 22, 2001||Sep 6, 2002||Flixel Ltd||Microelectromechanical display devices|
|WO2002084374A1 *||Dec 13, 2001||Oct 24, 2002||Onix Microsystems||Mems mirrors with precision clamping mechanism|
|WO2004037713A1 *||Oct 17, 2003||May 6, 2004||Koninklijke Philips Electronics N.V.||Method for manufacturing a micro-electromechanical device and micro-electromechanical device obtained therewith|
|WO2007027813A2||Aug 30, 2006||Mar 8, 2007||International Business Machines Corporation||Micro-cavity mems device and method of fabricating same|
|U.S. Classification||335/78, 257/415|
|International Classification||H01H51/22, H02N1/00, H01H1/00, G02B26/08|
|Cooperative Classification||H01H1/0036, G02B26/0841, G02B26/085|
|European Classification||G02B26/08M4E, H01H1/00M, G02B26/08M4M|
|Aug 26, 1996||AS||Assignment|
Owner name: REGENTS OF THE UNIVERSITY OF CALIFORNIA, THE, CALI
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:JUDY, JACK W.;MULLER, RICHARD S.;REEL/FRAME:008101/0197
Effective date: 19960801
|Feb 27, 2003||FPAY||Fee payment|
Year of fee payment: 4
|Feb 28, 2007||FPAY||Fee payment|
Year of fee payment: 8
|Feb 28, 2011||FPAY||Fee payment|
Year of fee payment: 12